It has become well established that there are major health benefits from regular endoscopic examinations of a patient's internal structures such as the alimentary canals and airways, e.g., the esophagus, stomach, lungs, colon, uterus, urethra, kidney, and other organ systems. Endoscopes are also commonly used to perform surgical, therapeutic, diagnostic, or other medical procedures under direct visualization. A conventional imaging endoscope used for such procedures includes an illuminating mechanism such as a fiber optic light guide connected to a proximal source of light, and an imaging means such as an imaging light guide to carry an image to as remote camera, or eye piece, or a miniature video camera within the endoscope itself. In addition, most endoscopes include one or more working channels through which medical devices such as biopsy forceps, snares, fulguration probes and other tools may be passed in order to perform a procedure at a desired location in the patient's body.
Navigation of the endoscope through complex and tortuous paths is critical to the success of the examination with minimum pain, side effects, risk or sedation to the patient. To this end, modern endoscopes include means for deflecting the distal tip of the scope to follow the pathway of the structure under examination, with minimum deflection or friction force upon the surrounding tissue. Control cables similar to bicycle brake cables are carried within the endoscope body in order to connect an articulation joint adjacent to the distal end to a set of control knobs at the proximal endoscope handle. By manipulating the control knobs, the operator is usually able to steer the endoscope during insertion and direct it to a region of interest. Common operator complaints about traditional endoscopes include their limited flexibility, limited column strength, and limited operator control of stiffness along the endoscope length.
Conventional endoscopes are expensive, hand assembled medical devices costing in the range of $25,000 for an endoscope, and much more for the associated operator console. Because of this expense, these conventional endoscopes are built to withstand repeated disinfections and use upon many patients. Conventional endoscopes are generally built of sturdy materials, which decreases the flexibility of the scope and thus can decrease patient comfort. Furthermore, conventional endoscopes are complex and fragile instruments that frequently need expensive repair as a result of damage during use or during a disinfection procedure.
Low cost, disposable medical devices designated for a single use have become popular for instruments that are difficult to clean properly. Single-use, disposable devices are packaged in sterile wrappers to avoid the risk of pathogenic cross-contamination of diseases such as HIV, hepatitis, and other pathogens. Hospitals generally welcome the convenience of single-use disposable products because they no longer have to be concerned with product age, overuse, breakage, malfunction, and sterilization. One medical device that has not previously been inexpensive enough to be considered truly disposable is the endoscope, such as a colonoscope, bronchoscope, gastroscope, duodenoscope, etc. Such a single-use or disposable endoscope is described in U.S. patent application Ser. No. 10/811,781, filed Mar. 29, 2004, and in a U.S. Continuation-in-Part patent application Ser. No. 10/956,007, filed Sep. 30, 2004, that are assigned to Scimed Life Systems, Inc., now Boston Scientific Scimed, Inc., and are hereby incorporated by reference.
The articulation joint adjacent to the distal tip of a conventional endoscope is typically made from complicated stamped and formed parts that are brazed together. The brazing operation is expensive and the metal articulation joint segments require special tooling to produce. In addition, adhesives are often used to assemble the articulation joint segments to each other. Therefore, a need exists for a method of producing articulation joints from low cost materials that are easily assembled for use in a low-cost medical device such as a disposable endoscope.